Gear case and propeller shaft bearing for outboard motors



p 9, 1952 E. c. KIEKHAEFER 2,609,783

GEAR CASE AND PROPELLER SHAFT BEARING FOR OUTBOARD MOTORS Filed May 11,1951 2 SHEETS-SHEET 1 ,1" 38 /4- i i I 1 l 2 1Z2 1 l '1 /9 i 20 /4 36 42a 42 25 3512/ 27 AZ 4/ E Z7 28 32 4a IN VEN TOR.

filler/rays Sept. 9, 1952 Filed May 11 1951 E. C. KIEKHAEFER GEAR CASEAND PROPELLER SHAFT BEARING FOR OUTBOARD MOTORS.

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INVENTOR. (721?!" fil kfia9 er mum Patenteri Sept. 1952 orFicE GEAR CASEAND PROPELLER. SHAFT BEARING FOR OUTBOARD MOTORS Elmer C. Kiekhaefcr,Cedarhurg, Wis.

Application May 11, 1951, Serial No. 225,813

8 Claims.

This invention relates to outboard motors and particularly to theunderwater unit thereof.

The invention provides a lower unit having an improved bearing and gearassembly and water intake means especially adapted for high speedoperation.

The principal object of the invention is to reduce the frontal area ofthe unit and the drag while providing for the adequate bearing supportof the propeller shaft at higher operating speeds of the motor.

Another object is to provide a lower unit adapted to transmit more powerat higher speeds without mechanical failure or breakage of the gearcase.

A more particular object is to support the full length of the propellershaft and prevent deflection of the shaft.

These and other objects and advantages will be more fully set forth inthe following description of the invention as illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a vertical, longitudinal cross-section of the outboard motorlower unit; and

Fig. 2 is a similar view of an alternate embodiment of the invention ina similar lower unit.

Units I and 2, shown in Figures 1 and 2, respectively, comprise thelower, underwater mechanisms of outboard motors which are adapted to besecured to the transom of a boat, not shown, and pivotally supported forturning on a vertical axis to effect the directional control of theboat.

Each lower unit supports a propeller 3 for rotation and includes thegear case 3. The hub 5 of propeller 3' carries the blades 6 of thepropeller which rotate at high speed andare subject to striking objectswhich can damage the gear case and interfere with the operation of themotor.

Units l and 2, are identical, except as hereinafter described, and carrythe lower end of the drive shaft 1 of each unit. In each embodiment ofthe invention the drive shaft 1 is connected at its upper end to theengine of the motor and carries the drive beveled gear 8 at its lowerend and in mesh with the driven beveled gear 9 mounted on the propellershaft It to drive propeller 3.

The gear case d comprises a single, cast member generally including thestrut l i, the enlarged torpedo section l2 and the skeg 13 which extendsas a thin, downwardly projecting fin from the underside of the torpedosection.

The strut l I is formed with a chamber [4 which opens upwardly from theupper planiform face [5 thereof and is secured by the forward and reartie bolts IB'and ll, respectively, to the lower end of the motor. Theupper and lower bearings l8 and 19, respectively, journally supportdrive shaft 1 in chamber M. The upper bearing [8 is seated in a suitablebore against the shoul der 20 formed in the strut H near the upper endthereof and with the seal 2i mounted thereover on shaft 1. The shoulder22 engages the inner race of bearing iii to transmit the axial thrust ofgear 3 thereto. The lower bearing I9 is preferably a needle or rollerbearing unit with a minimum outer diameter and is disposed within thelower end of strut H to support the'lower end of shaft I immediatelyabove torpedo section and gear 8.

The torpedo section l2 of gear case 4 is formed with a chamber 23 whichopens rearwardly thereof and communicates forwardly with the lower endof chamber Hi. The lower end of drive shaft 1 projects into chamber 23and carries gear 8 therein in an enlarged pocket forming a part ofchamber 23 in the gear case to accommodate the gears.

The forward bearing 24 is seated in the bored forward end of chamber 23and supports the forward end of shaft H3.

The larger bearing 25 is secured and fits a corresponding bore 2% at therear of chamber 23 and is disposed against the shoulder 2! formedtherein and facing rearwardly thereof. The'inner race of bearing 25supports directly thehub of gear 9 and the ring 28 axially secures theinner race of bearing 25 and the gear. The pin.29 secures the hub ofgear 9 and shaft it on which the gear is mounted and the shaft issupported intermediate the ends thereof.

The pump unit which supplies the engine of power head I with coolantunder pressure is mounted on shaft It rearwardly of bearing 25 andincludes the impeller 36 rotationally secured on shaft l6 within thepump body 3| which houses the impeller. Pump body 3| is cylindrical tofit Within bore 25 and is provided with suitable seals 32 and 33respectively engaging shaft ill and the walls of the torpedo to closechamber 23.

The inlet and outlet ports 34 and 35 of pump body 3| registerrespectively with the intake ports not shown and discharge passage 35formed in the gear case. Passage 36 extends from chamber 23 rearwardlyof seal 33 upwardly within strut II and is fitted with the seal 31 inthe up- 3 per face 15 of the strut to receive the lower end of deliveryconduit 38 connected to the coolant system of the motor.

The conical member 39 shown in Figure l fitted within the rear openingof chamber 23 engages the pump body 3! to secure the latter therein andto expand seal 33 against bore 26 to close the same tightly and securesalso bearing 25 against shoulder 22 to prevent axial displacement ofshaft l and gear 9. According to the invention the bearing 40 carried inthe rear end of member 35 is disposed to support the rear projecting endof shaft l0 against deflection and is dimensioned to provide a nominalclearance between the shaft and the bearing surface so that underordinary conditions of service no bearing load is exerted or carried andfrictional losses are substantially avoided. In the event of unduevibration or deflection of shaft If] as when propeller 3 strikes anobject bearing 40 supports shaft l8 against bending and misalignment.According further to the invention, the alignment of bearing to withbearings 2d and 25 is established by shaft It in the assembly of theunit and is maintained by the shoulder 21 and bearing 25 through pumpbody 31. The mechanical difliculties normally encountered in maintainingthe alignment of three spaced bearings is effectively avoided so thatthe clearances are maintained between bearing All and shaft H3. Thenormal clearances of the threads M of gear case 4 and member 353provides all the necessary radial adjustment of member 39 whichordinarily needs to be effected. In the assembly of the unit, thebearing 25, gear 9 and the pump may be inserted in bore 26 as asub-assembly. The shim 32 may be inserted between shoulder 21 andbearing 25 as required. As member 39 is turned in threads 4! the forwardface of the member contacts the rear face of pump body 3! and thealignment of bearing M3 is automatically effected. Member 39 is tightlysecured thereafter by further turning and tightening and the alignmentestablished by shaft if] is maintained accordingly.

The inner conical member 33 shown in Fig. 2 carries the roller bearingsM- which support the rear projecting ends of shaft ii! at all times andis adapted particularly for larger units where the shaft transmits ahigher power output, The outer cone 45 shown in Fig. 2 is threaded inthe rear open end of chamber 23 to engage the flange 45 of member 43 andsecure the latter in contact with the rear face of the pump body 2!. Aclearance provided between flange at and gear case provides for radialadjustment of member d3 which is established by shaft It and maintainedby tightening cone 45.

In both embodiments of the invention, the alignment of bearings 24 and25 and the bearings supporting the projecting end of shaft it isprovided for in the initial assembly of the unit and is only indirectlyaffected by manufacturing tolerances. Member 39 and cone 45 extendrearwardly of the strut II of the gear case i and are shaped to continuethe streamlines of torpedo 52 up to the hub 5 of propeller 3.

Various embodiments of the invention may be employed within the scope ofthe following claims.

I claim:

1. In an outboard motor lower unit, a gear case member having anenlarged torpedo section at the lower end of a narrower supportingstrut, said member comprising a cast housing having a chamber formedtherein and including a bore within the forward end of said torpedosection and a larger rear bore axially aligned with said first bore andspaced therefrom and opening rearwardly of said torpedo section, a driveshaft journally supported within said strut, a drive gear carried bysaid drive shaft within said chamber between said bores, a propellershaft extending from said chamber and extending through said larger boreand rearwardly of said gear case, a driven gear fixed on said shaft insaid chamber and in mesh with said drive gear, a first bearing carriedby said housing in said forward bore journally supporting the forwardend of said propeller shaft, a second bearing mounted within said largerbore rearwardly of said drive gear and supporting said shaftintermediate the ends thereof and said driven gear thereon, a shoulderformed within said larger bore facing the open end thereof and disposedto locate and support said second bearing against axial displacement, aclosure member secured within the open end of said bore against saidsecond bearing to secure the latter against said shoulder and to securesaid driven gear and propeller shaft against axial displacement, and athird bearing carried by said closure member supporting the rear end ofsaid propeller shaft and maintained in alignment with the alignment ofsaid first and second bearings by said. shoulder.

2111 an outboard motor lower unit, a gear case housing having a chamberformed therein and including a bore within the forward end thereof and alarger rear bore axially aligned with said first bore and spacedtherefrom and opening rearwardly thereof, a drive shaft and a drive gearcarried by said drive shaft within said chamber between said bores, apropeller shaft extending from said chamber and extending through saidlarger bore and rearwardly of said housing, a driven gear fixed on saidshaft in said chamber and in mesh with said drive gear, a first bearingcarried by said housing in said forward bore journally supporting theforward end of said propeller shaft, a second bearing mounted Withinsaid larger bore rearwardly of said drive gear and supporting said shaftintermediate the ends thereof and said driven gear thereon, a shoulderformed within said larger bore facing the open end thereof and disposedto locate and support said second bearing against axial and angulardisplacement, a closure member secured within the open end of said boreagainst said second bearing to secure the latter against said shoulderand to secure said driven gear and propeller shaft against axialdisplacement, and a third bearing carried by said closure membersupporting the rear end of said propeller shaft and maintained by saidshoulder in alignment with the alignment of said first and secondbearings initially established by the shaft.

3. In an outboard motor lower unit, a gear case housing having a chamberformed therein and including a bore within the forward end thereof and alarger rear bore axially aligned with said first bore and spacedtherefrom and opening rearwardly thereof, a drive shaft and a drive gearcarried by saiddrive shaft within said chamber between said bores, apropeller shaft extending from said chamber through said larger bore andprojecting rearwardly of said housing, a driven gear fixed on said shaftin said chamber and in mesh with said drive gear, a first bearingcarried by said housing in said forward bore journally supporting theforward end of said propeller shaft, a second bearing mounted withinsaid larger bore rearwardly of said drive gear and supporting said shaftintermediate the ends thereof and said driven gear thereon, a shoulderformed within said larger bore facing the open end thereof and disposedinwardly thereof and to locate and support said second bearing againstaxial and angular displacement, a closure member secured within the openend of said bore against said second bearing to secure the latteragainst said shoulder and to secure said driven gear and propeller shaftagainst axial displacement, and a third bearing carried by said closuremember and maintained by said shoulder in alignment with the alignmentof said first and second bearings initially established by the shaft anddisposed to support the projecting end of said propeller shaft against agiven maximum deflection.

4. In an outboard motor lower unit, a gear case housing having a chamberformed therein and including a bore within the forward end thereof and alarger rear bore axially aligned with said first bore and spacedtherefrom and opening rearwardly thereof, a drive shaft and a drive gearcarried by said drive shaft Within said chamber between said bores, apropeller shaft extending from said chamber through said larger bore andprojecting rearwardly of said housing, a driven gear fixed on said shaftin said chamber and in mesh with said drive gear, a

first bearing carried by said housing in said for- Ward bore journallysupporting the forward end of said propeller shaft, a second bearingmounted within said larger bore rearwardly of said drive gear andsupporting said shaft intermediate the ends thereof and said driven gearthereon, a shoulder formed within said larger bore facing the open endthereof and disposed inwardly thereof and to locate and support saidsecond bearing against axial and angular displacement, a closure membersecured within the open end of said bore against said second bearing tosecure the latter against said shoulder and to secure said driven gearand propeller shaft against axial displacement, and a third bearingcarried by said closure member and maintained by said shoulder inalignment with the alignment of said first and second bearings initiallyestablished by the shaft and disposed to support the projecting end ofsaid propeller shaft against a given maximum deflection, said shaftbeing otherwise supported by said first and second bearingsindependently of said third bearing.

5. In an outboard motor lower unit, a gear case housing having a chamberformed therein and including a bore within the forward end thereof and alarger rear bore axially aligned with said first bore and spacedtherefrom and opening rearwardly thereof, a drive shaft and a drive gearcarried by said drive shaft within said chamber between said bores, apropeller shaft extending from said chamber through said larger bore andprojecting rearwardly of said housing, a driven gear fixed on said shaftin said chamber and in mesh with said drive gear, a first bearingcarried by said housing in said forward bore journally supporting theforward end of said propeller shaft, a second bearing mounted Withinsaid larger bore rearwardly of said drive gear and supporting said shaftintermediate the ends thereof and said driven gear thereon, said housinghaving a shoulder formed at the inner end of said larger bore and facingthe open end thereof to locate and support said second bearing againstaxial and angular displacement, a cylindrical pump body disposed withinsaid bore rearwardly of and against said second bearing, a closuremember secured within the open end of said bore against said pump bodyto secure the latter therein and said second bearing against saidshoulder and tosecure said driven gear and propeller shaft against axialdisplacement, said closure member being subject to radial adjustment insaid bore and a third bearing carried by said closure member disposed tosupport the projecting end of said propeller shaft and maintained bysaid shoulder in alignment with the alignment of said first and secondbearings as initially established by the shaft.

6. In an outboard motor lower unit, a gear case housing having a chamberformed. therein and including a bore within the forward end thereof anda larger rear bore axially aligned with said first bore and spacedtherefrom and opening rearwardly thereof, a drive shaft and a drive gearcarried by said drive shaft within said chamber between said bores, apropeller shaft extending from said chamber through said larger bore andprojecting rearwardly of said housing, a driven gear fixed on said shaftin said chamber and in mesh with said drive gear, a first bearingcarried by said housing in said forward bore journally supporting theforward end of said propeller shaft, a second bearing mounted withinsaid larger bore rearwardly of said drive gear and supporting saidshaftintermediate the ends thereof and said driven gear thereon, said housinghaving a shoulder formed at the inner end of said larger bore and facingthe open end thereof to locate and support said second bearing againstaxial and angular displacement, a cylindrical pump body member disposedwithin said bore rearwardly of and against said second bearing, aclosure member Within the open end of said bore against said pump bodymember, means to secure said members in said bore and said secondbearing against said shoulder and to secure said driven gear andpropeller shaft against axial displacement, said closure member beingsubject to radial adjustment in said bore, and a third bearing carriedby said closure member disposed to support the projecting end of saidpropeller shaft and maintained by said shoulder in alignment with thealignment of said first and second bearings as established by the shaft.

7. In an outboard motor lower unit, a streamlined gear case housinghaving a torpedo section with a chamber formed therein and including abore within the forward end thereof and a larger rear bore axiallyaligned with said first bore and spaced therefrom and opening rearwardlythereof, a drive shaft and a drive gear carried by said drive shaftwithin said chamber between said bores, a propeller shaft extending fromsaid chamber through said larger bore and projecting rearwardly of saidhousing, a driven gear fixed on said shaft in said chamber and in meshwith said drive gear, a first bearing carried by said housing in saidforward bore journally supporting the forward end of said propellershaft, a second bearing mounted within said larger bore rearwardly ofsaid drive gear and supporting said shaft intermediate the ends thereofand said driven gear thereon, said housing having a shoulder formed atthe inner end of said larger bore and facing the open end thereof tolocate and support said second bearing against axial and angulardisplacement, a cylindrical pump body disposed rearwardly within saidbore against said second bearing, a closure member secured within theopen end of said bore against said pump body to secure the lattertherein and said second bearing against said shoulder and to secure saiddriven gear and propeller shaft against axial displacement, and a thirdbearing carried by said closure member disposed to support theprojecting end of said propeller shaft and maintained by said shoulderin alignment with the alignment of said first and second bearingsinitially established by the shaft, said closure member extendingrearwardly of said housing and forming the rear streamlines of thetorpedo section thereof.

8. In an outboard motor lower unit, a streamlined gear case housinghaving a torpedo section with a chamber formed therein and including abore within the forward end thereof and a larger rear bore axiallyaligned with said first bore and spaced therefrom and opening rearwardlyof the housing, a drive shaft and a drive gear carried by said driveshaft within said chamber between said bores, a propeller shaftextending from said chamber through said larger bore and projectingrearwardly of said housing, a driven gear fixed on said shaft in saidchamber and in mesh with said drive gear, a first bearing carried bysaid housing in said forward bore journally supporting the forward endof said propeller shaft, a second bearing mounted within said largerbore rearwardly of said drive gear and supporting said shaftintermediate the ends thereof and said driven gear thereon, said housinghaving a shoulder formed at the inner end of said larger bore and facingthe open end thereof to locate and support said second bearing againstaxial and angular displacement, a cylindrical pump body disposedrearwardly within said bore against said second bearing, a closuremember within the open end of said bore and disposed against said pumpbody, a cone member threaded in th open end of said bore to secure saidpump body therein and said second bearing against said shoulder and tosecure said driven gear and propeller shaft against axial displacement,and a third bearing carried by said closure member disposed to supportthe projecting end of said propeller shaft and maintained by saidshoulder in alignment with the alignment of said first and secondbearings as established by the shaft, said cone member extendingrearwardly of said housing and forming the rear streamlines of thetorpedo section thereof.

ELMER C'. KIEKHAEFER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS llumber Name Date 2,064,195 Michelis Dec. 15, 19362,434,312 Downs Jan. 13, 1948

